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  • Roma
  • Community Manager
2016-01-06T13:16:52+01:00
A)
53^2-47^2 =(53+47)(53-47)=100 \cdot 6 = 600
b)
137^2-37^2 =(137+37)(137-37)=174 \cdot 100 = 17400
c)
33^2-32^2 =(33+32)(33-32)=65 \cdot 1 = 65
d)
102 \cdot 98 =(100+2)(100-2) = 100^2 - 2^2 = 10000 - 4 = 9996
e)
18 \cdot 22 =(20-2)(20+2) = 20^2 - 2^2 = 400 - 4 =396
f)
37 \cdot 43 =(40-3)(40+3) = 40^2 - 3^2 = 1600 - 9 = 1591

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Wykorzystano wzór skróconego mnożenia
a^2 - b^2 = (a+b)(a-b)


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